This case outlines the management of a 61-year-old undiagnosed diabetic female who presented to the emergency department with signs and symptoms consistent with an acute Achilles rupture. The patient was referred to the foot and ankle clinic for routine management. Due to inconsistent clinical findings and progressive worsening of status in clinical exam, additional tests were ordered which revealed a 11.4 cm abscess in the posterior compartment of the right leg and an intact Achilles tendon. The patient underwent a staged incision and drainage with removal of all nonviable tissue resulting in a 4 cm x 1.4 cm defect. She underwent negative pressure wound VAC therapy resulting in full closure of the wound. This treatment led to resolution of the infection, limb salvage and preserved limb functionality.

We present a unique case in which an undiagnosed diabetic patient presented to the emergency department with symptomatology and history consistent with an acute Achilles tendon rupture. Despite having no constitutional symptoms, the patient was found to have a large abscess of the posterior compartment of the right lower leg.

This case report describes the diagnostic tests, surgical intervention and wound care techniques that eventually led to resolution of the infection and preserved limb functionality. It also draws attention to the fact that uncontrolled diabetes has the propensity to allow for large-scale infections in patients that have no open wounds or obvious sources of infection.

Diabetes mellitus (DM) presents a wide variety of systemic complications for affected patients. Of interest to this case is the diabetic individual’s reduced ability to mount an immune response, thereby masking the constitutional signs and symptoms of infection (fever, tachycardia, hypotension and tachypnea) [1]. In the previously undiagnosed patient, this abnormal presentation may delay and/or prevent proper diagnosis and treatment. The primary mechanism of immunosuppression is due to the altered structure and function of the diabetic polymorphonuclear cells, monocytes and macrophages compared to non diabetics [2,3]. The diabetic patient is also at an increased risk for infection as certain microorganisms become more virulent in a high glucose environment [4]. Microorganisms also demonstrate an increased adherence to diabetic cells as compared to non diabetic cells [5,6]. For this reason, physicians caring for diabetics need to have a high index of suspicion for possible infection even if vital signs and lab results remain within normal ranges, or if no clear source of infection is apparent [1,6].

Case Report

A 61-year-old Caucasian female presented to the emergency department due to increasing right calf pain, tenderness, swelling and inability to bear weight. Per the emergency department physician’s notes, the patient reported stepping out of an RV when she heard a pop and felt like her Achilles tendon was “overstretched”. She was not able to plantarflex on initial exam. No other injuries were reported. She denied fever, chills, nausea or vomiting. Vital signs were as follows: Blood pressure (BP) 158/75, Pulse 114, Temperature (Temp.) 36 °C (96.8 °F), Respiration rate (RR) 16 bpm, blood oxygen saturation (SpO2) 95%.

Pertinent past medical history included obesity and hypertension. She reported prior hand ganglion cyst excision, temporomandibular joint surgery and tonsillectomy. Her family medical history was remarkable for maternal diabetes and maternal aortic valve disease. She was a former smoker (1 pack/day, quit 5 years prior) and consumed 1-2 alcoholic beverages a month.

The review of systems upon arrival in the emergency department was negative. No abnormal integumentary findings were noted, specifically rash or erythema. Physical exam was positive for calf tenderness with palpation. A positive Thompson test was also documented. Vascular status was intact. Radiographs were ordered and revealed no bony abnormality or evidence of acute fracture (Figures 1a and b). The patient was diagnosed with an acute right Achilles tendon rupture and subsequently discharged. She was given a prescription of Vicodin and Ibuprofen and instructed to follow up with podiatry within a week.

The patient followed up as instructed two days later at the foot and ankle clinic. She stated that she developed a blister to her right posterior heel and noticed redness to her right calf. She rated her pain as 10/10. She denied nausea, fever, vomiting, chills and diarrhea. Vital signs were as follows: BP 155/89, Pulse 89, Temp. 36.7 °C (98.1 °F), RR 16, SpO2 96%.

On physical exam, she was neurovascularly intact. Significant global non-pitting edema was noted to the right ankle. A superficial bulla was noted to right posterior heel with serous drainage. Erythema was also present involving the posterior leg and foot. The musculoskeletal exam was positive for extreme guarding to right lower extremity. There was a negative Thompson’s test, in contrast to what the emergency department provider had documented. There was suspicion for infection; however, no obvious portal of entry was evident.

The patient’s diagnosis was then modified to acute right Achilles tendon rupture with cellulitis. The cellulitis was thought to have stemmed from the bulla secondary to traumatic edema. The patient was placed in a CAM boot, instructed to perform daily dressing changes to the bulla and to return to clinic in two days for re-evaluation. A venous duplex was ordered and reported as negative for deep vein thrombosis. An MRI was also ordered at that time due to suspicion of infection.

The patient returned to the podiatry clinic two days later. She stated she had been compliant with non-weight bearing and dressing changes. She reported a perceived increase in posterior heel edema. Her vitals were as follows: BP 163/89, Pulse 94, Temp. 36.3 °C (97.4 °F), Resp. 15, SpO2 95%.

Upon repeat clinical exam, the patient remained neurovascularly intact and extreme tenderness along the posterior lower leg was noted. Erythema and edema had worsened. Redness extended from her heel to the knee, both anterior and posteriorly. Expressible purulence was noted from the bulla which had increased in size and spread to her lateral heel. The posterior heel at the Achilles insertion site was enlarged and there was noticeable fluctuance, indicating an underlying abscess.

A CBC was ordered and revealed a WBC count of 17,700 with a left shift. Although the patient had no previous diagnosis of DM, her fasting glucose was 268 mg/dL with an HbA1C of 10.5%. ESR was 105 and CRP was 23.7. Cultures were taken from the purulent bulla and revealed methicillin resistant staphylococcus aureus bacteria.

The patient was admitted to the hospital and started on IV Vancomycin. The previously ordered MRI revealed an 11.4 cm fluid collection present in the posterior compartment of the leg (Figure 2a-d). The Achilles tendon was fully intact with no signs of rupture (Figure 2c).

The patient was consented for an incision and drainage of the purulent bulla in the operating room to be performed the following day. The incision and drainage was performed with the patient in the prone position. After an appropriate sterile prep was achieved, attention was directed to the bulla at the Achilles tendon insertion on the posterior aspect of the right heel where a stab incision was made (Figure 3). The stab incision was extended proximally until purulent drainage ceased at the level of the mid-calf.

Approximately, 75 cc of purulent drainage was evacuated from the leg. Three liters of normal saline was used for irrigation of the leg. Upon completion of the procedure, major muscular and tendinous structures, namely the Achilles tendon, were noted to be viable. The infection was confined to the posterior compartment only. The macerated, non-viable skin where the original bulla had been located was excised leaving an approximately 4 cm x 1.4 cm void over the Achilles tendon insertion [Figure 4].The wound was reapproximated using a combination of retention sutures and a vessel loop to reduce tension to the area (Figure 4). The wound was then packed and covered with a sterile dressing. Daily packing changes were performed with a repeat washout of the leg performed 72 hours later.

Figure 3 Purulent drainage from the bulla on the posterior leg upon stab incision.

Figure 4 Postoperative clinical appearance, demonstrating the extent of the incision required to ensure complete evacuation of the purulence. Vessel loop employed in a crisscross fashion in order to relieve tension. Note void with exposed Achilles tendon.

At the second wash-out, all purulence was noted to be absent and all muscular and tendinous structures remained viable. Partial primary closure was performed at the proximal aspect of the incision. The distal portion could not be closed. A vessel loop in a crisscross fashion was again employed to assist with reapproximation. Vacuum assisted closure therapy of the wound (wound VAC) was then initiated over the exposed Achilles tendon and along the incision. The patient’s WBC normalized three days postoperatively. The patient was medically managed for her undiagnosed diabetes.

Wound VAC changes were performed every other day while the patient was hospitalized. Upon discharge from the hospital, the patient received daily infusions of intravenous (IV) vancomycin for two weeks and all dressing changes were performed by enterostomal therapists. Although the infection had been eradicated, the challenge of keeping the exposed Achilles tendon viable for limb functionality remained.

Results

Over the next several weeks, the patient remained non-weightbearing and continued wound VAC therapy. At four weeks postoperatively, granulation tissue began to form over the tendon (Figure 5). The tendon appeared viable throughout the entire process; however, there was noticeable contracture during this period of non-weight bearing. The patient continued this course with regular wound VAC and dressing changes at a wound care center. At approximately four months postoperatively, complete granulation over the Achilles tendon and skin re-epithelialization was noted. No additional surgical intervention was needed.

Upon complete closure of the wound, the patient began physical therapy to regain ankle range of motion, strength and stability. After eight weeks of therapy, she was able to attain adequate ankle dorsiflexion. She remains completely healed with a functional limb 26 months post initial presentation (Figure 6).

Discussion

To our knowledge this is the first case report of deep posterior leg compartment infection in an undiagnosed diabetic patient initially misdiagnosed as an Achilles tendon rupture. On initial presentation to the emergency department and initial follow-up at the podiatry clinic, the patient’s large infection was masked due to the fact she was diabetic, albeit undiagnosed. She did not exhibit any constitutional symptoms of infection including fever, tachycardia, hypotension, or tachypnea. Additionally, there was no obvious portal of entry for the infection at the time of presentation.

In this case, there were key steps that ultimately led to limb salvage. The first was made by the emergency department physician by stressing the importance of prompt follow-up at the foot and ankle clinic for immediate management. The second key step was the foot and ankle physician performing the repeat physical exam from presentation to the emergency department. The negative repeat Thompson test led the provider to consider a broader differential diagnosis (Achilles tendon rupture with cellulitis vs deep vein thrombosis vs infection). Additional tests were then ordered to help narrow the differential even though the patient wasn’t demonstrating any constitutional signs of infection.

The two day follow up period as ordered by the foot and ankle specialist facilitated a prompt diagnosis and admission to the hospital immediately after review of the newly ordered labs and imaging. The timely diagnosis, admission, and incision and drainage ensured that the infection did not spread to other compartments or render the Achilles tendon nonviable.

Following initial management, additional steps were also taken to ensure full future functionality of the limb. The repeat incision and drainage allowed appropriate assessment of the infected structures prior to definite closure to ensure limb viability. The decision to maintain daily infusions of IV antibiotics for two weeks postoperatively prevented recurrence and non-weight bearing status allowed for appropriate granulation tissue to form over the tissue void and exposed tendon. Alternative wound care products which may have resulted in faster would closure were unavailable due to the patient’s insurance. Despite this limitation, wound VAC therapy was successful at gaining full would closure.

The final step which ensured limb viability and functionality was the referral to physical therapy in order to address the acquired equinus contracture. This referral was purposefully delayed until full would closure was achieved as early mobilization may have resulted in wound opening, and compromised healing, ultimately prolonging the course of treatment.

In conclusion, diabetic infections present unique challenges; however, when the proper precautions are taken limb salvage can be achieved.

by JM García-Sánchez1, A Ruiz-Valls1, A Sánchez-García1, A Pérez-García1

The Foot and Ankle Online Journal 11 (1): 2

Diabetes mellitus is one of the most prevalent diseases worldwide and an important cause of morbidity and mortality. Of relevance, due to its complicated management, morbidity and cost associated, is the diabetic foot. Here we present a case of a 51 year-old male diagnosed with long-standing decompensated Diabetes mellitus with a 2 year history of a foot ulcer. After debridement of the ulcer, preservation of the bony structure was achieved by covering it with a fillet flap. The therapeutic management in patients with advanced diabetic foot should be individualized based on patient characteristics. Oftentimes, conservative amputations entail the need of complex surgical techniques, however, it allows the patient to retain their independence and an improved quality of life.

Diabetes mellitus (DM) is one of the most common diseases worldwide with a global prevalence of 8.5%, and increasing every year. Sustained hyperglycemia derives in numerous complications, mostly caused by macro and microangiopathy [1], of special importance are Diabetic Foot Ulcers (DFUs).

Diabetic Foot Ulcers represent an important healthcare issue due to the elevated morbidity, complexity of its management and elevated costs associated with this disease [2]. DFUs have a global prevalence of 6.3% and have a higher prevalence in DM type 2 and male patients [3]. Neuropathy is the most important risk factor for the development of DFUs. Moreover, the addition of different factors such as the of loss of skin integrity, existence of foot deformities (Hallux Valgus, Charcot’s arthropathy, etc.), and peripheral vascular disease ultimately lead to the formation of DFUs [4].

The course of healing the DFU is arduous due to the impaired cicatrization and granulation processes in these patients, which is frequently complicated with superimposed infections. Some cases, especially when osteomyelitis is present, require limb amputation as the sole therapeutic option. However, it is imperative to remain as conservative as possible, since amputations suppose a great psychological and functional impact that can pose a decrease in quality of life.

Here we present a case of a patient with a complicated DFU that was managed with conservative surgical treatment without undergoing amputation.

Case Report

A 51 year old male was first evaluated in the outpatient setting for a 1-year history of a DFU on the right foot. His medical history included a atrial fibrillation, dyslipidemia, hypertension, and a poorly controlled insulin-dependent DM with development of retinopathy, nephropathy and cardiac disease. The patient was also an active smoker with over 30 years of smoking history. A transmetatarsal amputation from the 2nd to the 5th toes on the right foot was previously carried out in a different hospital due to inadequate healing of a DFU. The surgical wound was complicated with a dehiscence, which remained as an ulcer that impeded the patient from ambulating.

The physical examination showed a lateral subluxation of the first metatarsophalangeal joint, an ulcer on the amputation stump, with granulation on the base and no inflammatory signs, proliferative signs, dermatosclerosis or hyperpigmentation of the skin edges (Figure 1). Additionally, the patient presented signs of chronic venous insufficiency, hence the induration hindered lower limb distal pulse examination. Plantar protective sensation was severely diminished.

An MRI was performed, which showed findings suggestive of osteomyelitis of the remnants of the 3rd, 4th and 5th toe, the anterior portion of the cuboid bone, and the navicular bone of the right foot. These findings were later confirmed with a gamma scan. The CTA scan showed bilateral permeability of the aortoiliac, femoropopliteal, and distal infrapopliteal trunks.

Given these findings a new surgical approach was conducted, with resection of the remnants of the 2nd to 5th toes, cuboid bone, cuneiform bones, as well as the anterior portion of the navicular bone (Figure 2), a fillet flap from the hallucis and the plantar skin was performed to provide coverage of the cutaneous defect (Figure 3).

The pathology report indicated the presence of a verrucous squamous cell carcinoma. However, no infiltrative component was seen in the specimen and the margins were disease free.

Figure 1 A 51 year old male with a lateral luxation of the metatarsophalangeal joint of the hallucis (Left). Ulcer presence on the amputation stump (Right). Frontal (Left) and plantar (Right) view.

Figure 2 Surgical excision of the remnants of the 2nd to 5th toes, cuboid bone, cuneiform bones, as well as the anterior portion of the navicular bone.

The postoperative course was uneventful with a favorable healing towards the resolution of the surgical wound, which was supported by a tight glucose control and a smoking cessation program. Two months after the intervention the patient has a healthy-appearing stump that allows ambulation (Figure 4).

Figure 3 Foot defect after resection (Left). Coverage with a fillet flap from the hallucis and the plantar skin (Right).

Figure 4 Postoperative result two months after the intervention. Frontal (Left) and posterior (Right) view.

Discussion

Complicated diabetic foot poses a risk of amputation and early mortality in diabetic patients. With a 10-fold increase in amputation rate of the lower limb for diabetic patients, according to WHO. Furthermore, the mortality rate is also increased 3-fold within a year of the amputation compared to non-amputated diabetic patients [6].

The course of DFUs is usually difficult owing to a deficient granulation and cicatrization, and commonly complicated with superimposed infections. DFUs that persist over time can sometimes lead to malignant transformation; most frequently squamous cell carcinoma [5]. All of these result in wide surgical excisions and, sometimes inevitably amputations.

There are different amputation levels of the lower limb, those that result in above-the-ankle amputation are considered major amputations, and those that spare the ankle are defined as minor amputations [7]. Regarding amputation-related-mortality, Evans et al, showed a mortality of 20% in the 2-year follow-up after a minor amputation compared to the 52% seen in patients who underwent a major amputation [8].

Numerous studies support the need to be as surgically conservative as possible, with limb conservation procedures, since energetic output is increased progressively as an amputation becomes more proximal [9]. Moreover, several patients present with several comorbidities, as in the case presented, and are non-candidates for rehabilitation after major amputations. Hence, preservation of the majority of the limb with partial minor amputations can result in an improved functional status [10]. Likewise, minor amputations may confer the possibility to ambulate for short distances without the need of prosthesis, allowing the patient to perform many daily-living activities, and thus, having a major impact on quality of life [8]. In some cases, in order to achieve minor amputations, the complexity of the surgical techniques is considerably higher and are often unconventional procedures that surgeons might not be familiarized with. In the case presented, due to patient conditions, impaired sensibility, presence of osteomyelitis, and the condition of the foot soft tissues, initially the decision was to perform a major amputation. Nevertheless, the scarce possibilities for adaptation to a prosthetic device and ambulation after amputation, a more conservative approach was planned. Therefore, preservation of the non-osteomyelitic bone and coverage of the skin defect with an adipocutaneous fillet flap from the hallux and the plantar surface provided a stable coverage without any added morbidity.

The fillet flap is well described in the literature as an alternative for large defects that require coverage without sacrificing the length of the extremity [11]. It provides superb mechanical stability plus an added quasi-normal sensitivity to the stump. Additionally, utilizing plantar tissue also provides an excellent, and long-lasting, surface for the stump [12].

Conclusion

Diabetic patients with DFUs should undergo individualized treatment based on their characteristics. In certain cases, a more conservative amputation, despite being more technically challenging, allows the patient to have a better quality of life as well as more independence.

Background: Ankle fractures in diabetics with secondary complications are more prone to postoperative complications than ankle fractures in diabetics without secondary complications. This study retrospectively compared the post injury complications of foot and ankle fractures in diabetics with and without secondary complications. Secondary complications of diabetes mellitus include peripheral arterial disease, nephropathy, and/or peripheral neuropathy. Uncomplicated diabetics did not have any of these end organ diseases associated with diabetes. Our hypothesis was that foot and ankle fractures in complicated diabetics would incur more post injury complications than uncomplicated diabetics.Materials and Methods: We contrasted the post injury complications of foot and ankle fractures in 25 complicated diabetics with15 uncomplicated diabetics.Results: At an average follow-up of 33.8 weeks we established that foot fractures in complicated diabetics had a non significant trend of a 2.8 times increase in overall post injury complications versus foot fractures in uncomplicated diabetics. Furthermore, with an average follow up of 28.8 weeks we demonstrated a non significant tendency of a 1.4 times increase in overall post injury complications of ankle fractures in complicated diabetics compared to ankle fractures in uncomplicated diabetics. Lastly, with a mean follow up of 33.7 weeks we found insignificant trends of a 1.7 times increase in overall post injury complications and a 2.8 times increase in noninfectious complications (malunion, delayed union, nonunion or Charcot neuroarthropathy) in complicated diabetic foot and ankle fractures contrasted to uncomplicated diabetic foot and ankle fractures.Conclusion: Foot and ankle fractures in complicated diabetics are presumably at an increased risk of developing a post injury complication compared to uncomplicated diabetics. Specifically, foot fractures should be treated similar to ankle fractures in complicated diabetics with an extended period of non-weight-bearing in a total contact cast. Mandatory post injury clinical evaluation for peripheral arterial disease, peripheral neuropathy and nephropathy should be implemented. This analysis will be used as a template for a future prospective comparative study evaluating foot and ankle fractures in complicated and uncomplicated diabetics with a power analysis to achieve statistical significance.

In 2010 it was projected that 25.8 million people in the United States had diabetes mellitus representing 8.3% of the population with another 7 million undiagnosed.[1]

The first report of diabetes mellitus affecting bone healing was an animal study in 1968 by Herbsman, et al.[2] They found that rats with uncontrolled diabetes mellitus had reduced fracture healing compared to the healthy controls.

Other animal studies have confirmed these results and have found that fractures in diabetic rats treated with insulin improved bone healing.[3-6] In the earliest human case report, Cozen reviewed 9 diabetics with lower extremity fractures and contrasted them with 9 matched controls. He verified a delayed time to union in the diabetic patients.[7]

Several studies have demonstrated increased complications in diabetic ankle fractures compared to the healthy controls.[8-12] However, several recent studies have shown that ankle fractures in diabetics without comorbidities (uncomplicated diabetics) had complication rates similar to the controls. Conversely, complicated diabetics (peripheral neuropathy, nephropathy and peripheral arterial disease) had significantly increased complications.[13-15] However, to the best of our knowledge, in the English literature, there have been no studies examining the natural history of diabetic foot and ankle fractures concomitantly. Thus, a retrospective review of 40 patients with diabetes mellitus who sustained a foot and/or ankle fracture was performed.

Methods and Patients

On July 26, 2012, the Western Pennsylvania Allegheny Health System Institutional Review Board accepted this as an exempt study. A retrospective review of patient charts, radiographs, and operative reports with diagnosis codes for “diabetes mellitus” and “fracture” to the foot and/or ankle was assembled. Complicated diabetics were diagnosed with peripheral neuropathy (PN), peripheral arterial disease (PAD) and/or nephropathy. Uncomplicated diabetics did not have any of these end organ diseases.[16,17] PN was diagnosed when the patient could not detect the 5.07 Semmes Weinstein monofilament. PAD was diagnosed if the patient had been revascularized in the past or when the patient had non palpable dorsalis pedis or posterior tibial pulses.

Nephropathy was diagnosed when the patient had a serum creatinine of > 1.5.[11] Charcot neuroarthropathy was defined as bone fragmentation, bone absorption and boney consolidation.[18]

Superficial infections were categorized based on the need for only oral antibiotics and local wound care. Deep infections were delineated when the wound required intravenous antibiotics and surgical debridment.[11]

A nonunion was defined when a minimum of 9 months has passed and there are no interval changes consistent with a union on serial radiographs. A delayed union had decreased bone healing on serial radiographs.

The type of treatment was at the judgment of the attending foot and ankle surgeon. All patients with an ankle fracture underwent open reduction and internal fixation (ORIF) with plates and screw fixation of the fibula. Also, the medial malleolar fixation was accomplished with screws or tension banding. Syndesmotic fixation was accomplished with tri-cortical or quad-cortical screws when appropriate. All ankle fractures received preoperative antibiotics with continuation of antibiotics through the hospital course for open fractures. Non-weight-bearing (NWB) was generally instituted for a minimum of 7 weeks in a total contact cast (TCC) with transitioning to weight-bearing (WB) for a minimum of 4 weeks in a fracture walker for postoperative ankle fractures.

Forefoot fractures (toe and metatarsal) were commonly allowed WB in a surgical shoe or fracture walker for at least 2 weeks before transitioning to a sneaker. Patients were usually followed up at 2 week and subsequently 1 month intervals until fracture union. At most visits, medial oblique, anteroposterior and lateral radiographs were obtained to assess fracture healing.

There were a total of 40 diabetic foot and ankle fractures with an average follow up of 31.7 (4-137) weeks. Patient ages ranged from 43 to 85, with a mean of 62.00±10.34 (standard deviation). There were a total of 22 females (55%) and 18 males (45%). Patient BMI ranged from 21.81 to 56.35 with a mean of 34.11±5.91. Thirty seven (93%) experienced closed injuries while three (7%) experienced open injuries. Nineteen patients (48%) were treated non-operatively (toe, metatarsal and cuboid fractures) and 21 (52%) were treated operatively (ankle and a calcaneal avulsion fracture).

Also, there was no statistical difference between uncomplicated and complicated diabetes with regards to the frequency of sex and treatment (Table 1).

There was no statistical difference between complicated and uncomplicated diabetics regarding the number of weeks WB (8.56±5.64, 7.40±6.70, p = .56) and non-weight-bearing (7.93±4.17, 7.75±3.25, p = .90). Along with no statistical significance among complicated and uncomplicated diabetics (table 2) in weeks to clinical union (10.12±6.35, 9.27±3.44, p=.64) and radiographic union (14.76±7.20, 12.87±5.87, p = .40).

Twenty three foot fractures were included in the retrospective review with an average follow up of 33.8 weeks. (Table 3). Eighteen (78%) were complicated diabetics while five (22%) were uncomplicated diabetics. Ten (56%) of the complicated diabetics experienced a post injury complication.
Conversely, only 1 (20%) uncomplicated diabetic experienced a post injury complication. A two sided Fisher’s Exact test indicated no significant difference in proportion of patients experiencing post injury complications between complicated and uncomplicated diabetic groups (p = .32).

Moreover, there were a total of seventeen ankle fractures with a mean follow up of 28.8 weeks. (Table 4). Seven (41%) had complicated diabetes while 10 (59%) had uncomplicated diabetes. Among complicated diabetics, 4 (57%) experienced a post injury complication, whereas 4 (40%) of uncomplicated diabetics experienced a post injury complication. A two sided Fisher’s Exact test indicated no significant difference in proportion of patients who experienced a post injury complication between complicated and uncomplicated diabetic groups (p = .64).

Table 6: Complications among diabetes type.

Table 7: Complications among foot and ankle fractures.

Further analyses evaluated the relationship between severity of complicated diabetes (PN+ PAD + nephropathy) and the number of post injury complications sustained by each patient. Eighteen diabetics (72%) were diagnosed with one complicating factor, six (24%) were diagnosed with two complicating factors, and one (4%) was diagnosed with all three complicating factors.

Table 8: Non-infectious complications by diabetes type and total fractures.

The relationship between diabetes type and the presence of a post injury complication when collapsing across all types of injuries was conducted (Table 6).Fourteen (56%) complicated diabetics experienced one or more post injury complications. Among uncomplicated diabetics, 5 (33%) experienced one or more post injury complications. A two-sided Fisher’s Exact test indicated no relationship between diabetics type and the presence of injury complications (p = .20). All diabetic foot and ankle fracture complications are described in Table 7. There were no amputations performed in any of the complicated or uncomplicated diabetic foot or ankle fractures.

This retrospective review of the natural history of 40 diabetic fractures is the first to evaluate foot and ankle fractures together. In regards to foot fractures (Figure 1), 56% (10/18) of foot fractures in the complicated group experienced a post injury complication while only 20% (1/5) of the uncomplicated group sustained a post injury complication (p = .32). Although not statistically significant, there was a 36% (2.8 times) increase in complications with complicated diabetics who sustained a foot fracture (Table 3). Kristiansen described a diabetic second metatarsal shaft fracture that was allowed to weight bear immediately with a bandage. Three months later the metatarsal fracture developed Charcot neuroarthropathy. He concluded that even metatarsal fractures should be immobilized and weight-bearing must be deferred until fracture healing is complete.[20] The foot fractures (metatarsal, phalanx, and cuboid) in this study were allowed to WB immediately in a surgical shoe or fracture walker. The authors hypothesize that a more aggressive immobilization regimen such as non-weight-bearing or total contact casting should be considered to decrease adverse outcomes in the complicated diabetic group.

Figure 2: Initial and 12 week radiographs of a bimalleolar ankle fracture in a complicated diabetic.

In evaluating 17 operatively treated ankle fractures (Figure 2), the complicated diabetic group had a 57% (4/7) post injury complication rate while the uncomplicated diabetic group had 40% (4/10) post injury complication rate (p = .64). Many studies, including a meta-analysis of 356 ankle fractures, have established an overall increase in complications in diabetic ankle fractures compared to non diabetics.[21-27] Additionally, Wukich, et al., retrospectively confirmed that complicated diabetics had a 3.8 (p = .003) times amplified risk of a post injury complication.[11] In our study, there was a non significant trend of a 17% (1.4 times) increased complication rate for ankle fractures in the complicated diabetic group compared to the uncomplicated diabetic group. However, in the Wukich, et al., study there was total of 59 uncomplicated diabetics and 46 complicated diabetics which achieved statistical significance.[11] To attain statistical significance in our study, approximately 90 additional ankle fractures would need to be evaluated.

Compiling all diabetic foot and ankle fractures there were a total of 25 complicated and 15 uncomplicated fractures. Post injury complications occurred in 56% (14/25) of the complicated diabetics and in 33% (5/15) of the uncomplicated diabetics (p = .20). Also, 47% (9/19) of the complicated diabetics experienced a non-infectious complication compared to only 19% (4/21) of the uncomplicated diabetics (p = .38). Thus, there was a non significant tendency of a 23% (1.7 times) elevated risk of developing a post injury complication in the complicated diabetics with a 28% (2.4 times) increased risk of having a non-infectious complication. This increase is on par with Wukich, et al., who found a 3.4 times increased risk of developing a non-infectious complication ankle fractures in complicated diabetics. Also, the complicated diabetic group took almost 2 weeks longer for radiographic union compared to the uncomplicated diabetic group (14.76±7.20, 12.87±5.87, p = .40). While there was no statistical difference between the groups, the overall increase in healing time for all diabetic fractures is consistent with other studies.[2-7,12,22]

On the other hand, in our study no diabetic fractures resulted in an amputation. The literature has demonstrated amputation rates of diabetic ankle fractures ranging from 4 -17%.[9,23,28] Our 0% amputation rate is most likely due to the fact that we are not located at a level 1 trauma center and only had 3 (7%) open ankle fractures with no open foot fractures. Open diabetic ankle fractures traditionally have very poor outcomes with a 38% amputation rate in a case study by White, et al., in 2003.

A novel analysis evaluated the relationship between the severity of complicated diabetes and the number of post injury complications sustained by each patient. Eighteen diabetics (72%) were diagnosed with one complicating factor and seven (28%) were diagnosed with two or more complicating factors. Six (78%) of the diabetics with 2 or more complicating factors experienced at least one post injury complication compared to 8 (44%) of the diabetics with only 1 complicating factor (p = .14). This also showed a non significant propensity as the number of diabetic complicating factors increases, the amount of complications increases as well (1.7 times higher).

The most obvious weakness of our evaluation was the study being underpowered. This was because of the relatively small number of diabetic patients reviewed. Over 30 patients had to be excluded from the study due incomplete medical records including no height or weight being recorded, complications described too broad for interpretation, and radiographs/charts missing. These patients may have helped influence the data to become significant.

The other main weakness was the retrospective nature of the study. Retrospective studies are based on the correctness of patient charts/radiographs and thus information collected is only as accurate as the medical information documented. Also, this study also did not evaluate other complications such as deep vein thrombosis, thromboembolism, stroke, or myocardial infarction.

Furthermore, there could have been measurement bias as there was not a standard protocol initiated. However, all diabetic ankle fractures did receive ORIF with treatment based on standard fixation principles. Also, all diabetic foot fractures except one calcaneal avulsion fracture, were treated non-operatively in a surgical shoe or fracture walker.

Non-responder bias is also a part of this study since some patients were followed longer than others. If some patients were observed longer more complications could have been discovered. Most foot fractures were followed until fracture union and were not followed up thereafter. Moreover, there also could have been interview bias as the treating foot and ankle surgeon determined if there was a complication and recorded this in the patient’s clinical chart.

Conclusion

Although not statistically significant, the trend of increased complication rate for foot fractures in complicated diabetics leads us to believe that foot fractures should be treated in the same manner as ankle fractures in complicated diabetics. Post injury clinical evaluation for PAD, PN and nephropathy should be considered. This analysis will be used as a template for a future prospective study comparing complicated and uncomplicated diabetic foot and ankle fractures.